12,986 research outputs found
Strapdown calibration and alignment study. Volume 2 - Procedural and parametric trade-off analyses document Final report
Parametric and procedural tradeoffs for alignment and calibration of inertial sensing uni
Strapdown calibration and alignment study. Volume 2 - Procedural and parametric trade- off analyses document
Techniques for laboratory calibration and alignment of strapdown inertial sensing unit - procedural and parametric trade-off analyse
Path decompositions of chains and circuits
Expressions for the path polynomials (see Farrell [1]) of chains and circuits
are derived. These polynomials are then used to deduce results about node disjoint path decompositions of chains and circuits. Some results are also given for decompositions in which specific paths must be used
The window of visibility: A psychological theory of fidelity in time-sampled visual motion displays
Many visual displays, such as movies and television, rely upon sampling in the time domain. The spatiotemporal frequency spectra for some simple moving images are derived and illustrations of how these spectra are altered by sampling in the time domain are provided. A simple model of the human perceiver which predicts the critical sample rate required to render sampled and continuous moving images indistinguishable is constructed. The rate is shown to depend upon the spatial and temporal acuity of the observer, and upon the velocity and spatial frequency content of the image. Several predictions of this model are tested and confirmed. The model is offered as an explanation of many of the phenomena known as apparent motion. Finally, the implications of the model for computer-generated imagery are discussed
Satellite voice broadcast. Volume 1: Executive summary
An Executive Summary of the Satellite Voice Broadcast System Study designs are synthesized for direct sound broadcast satellite systems for HF-, VHF-, and Ku-bands. Methods are developed and used to predict satellite weight, volume, and RF performance for the various concepts considered. Cost and schedule risk assessments are performed to predict time and cost required to implement selected concepts. Technology assessments and tradeoffs are made to identify critical enabling technologies that require development to bring technical risk to acceptable levels for full scale development
The Magellanic system X-ray sources
Using archival X-ray data from the second XMM-Newton serendipitous source
catalogue, we present comparative analysis of the overall population of X-ray
sources in the Large and Small Magellanic Clouds. We see a difference between
the characteristics of the brighter sources in the two populations in the X-ray
band. Utilising flux measurements in different energy bands we are able to sort
the X-ray sources based on similarities to other previously identified and
classified objects. In this manner we are able to identify the probable nature
of some of the unknown objects, identifying a number of possible X-ray binaries
and Super Soft Sources.Comment: 4 pages, 2 figures. Poster to appear in proceedings of IAU Symposium
256, The Magellanic System: Stars, Gas, and Galaxies. Keele Univeristy, U
Searching for X-ray sources in nearby late-type galaxies with low star formation rates
Late type non-starburst galaxies have been shown to contain X-ray emitting
objects, some being ultraluminous X-ray sources. We report on XMM-Newton
observations of 11 nearby, late-type galaxies previously observed with the
Hubble Space Telescope (HST) in order to find such objects. We found 18 X-ray
sources in or near the optical extent of the galaxies, most being point-like.
If associated with the corresponding galaxies, the source luminosities range
from erg s to erg s. We
found one ultraluminous X-ray source, which is in the galaxy IC 5052, and one
source coincident with the galaxy IC 4662 with a blackbody temperature of
keV that could be a quasi-soft source or a quiescent neutron
star X-ray binary in the Milky Way. One X-ray source, XMMU J205206.0691316,
is extended and coincident with a galaxy cluster visible on an HST image. The
X-ray spectrum of the cluster reveals a redshift of and a
temperature of 3.60.4 keV. The redshift was mainly determined by a cluster
of Fe XXIV lines between the observed energy range keV.Comment: 8 pages, to appear in MNRA
Strapdown calibration and alignment study. Volume 1 - Development document Final report
Calibration and alignment techniques for inertial sensing uni
- …